As the World Wide Web (WWW) becomes increasingly popular, there is a general concern about the content of Web sites. Ideally, users should have control over the content which enters their homes.
A recently established standard allows a content specification as meta data in an object header using existing Web protocols such as the hypertext transfer protocol ("HTTP"). The Platform for Internet Content Selection ("PICS") protocol specifies one method of sending meta-information concerning electronic content. PICS is a Web Consortium Protocol Recommendation (see http://www.w3.org/PICS). PICS was first used for sending values-based rating labels, such as "How much nudity is associated with this content," but the format and meaning of the meta-information is fully general. In PICS, meta-information about electronic content is grouped according to a "rating service" or producer-and-intended-usage of the information, and within one such group, any number of categories or dimensions of information may be transmitted. Each category has a range of permitted values, and for a specific piece of content, a particular category may have a single value or multiple values. In addition, the meta-information group (known as a "PICS label") may contain expiration information. There are also facilities for permitting a PICS label to apply to more than one piece of electronic content. Each PICS label for a specific piece of electronic content may be added or removed from the content independently.
For example, an image file may be sent from a server with a single PICS label whose "rating service" field indicates it contains values-based rating labels according to the "SafeSurf" rating system. The HTTP protocol has been augmented with request headers and response headers that support PICS. The technical bodies which define other common application protocols, such as NNTP, are now also considering adding PICS support. As part of these protocols, a list of the types of PICS labels desired may be included with a request. PICS also specifies a query format for receiving PICS information from a central label bureau server. A sample PICS label is: (PICS-1.1 "http://the.rating.service" label for "http://the.content" exp "1997.07.01T08: 15-0500" r (n 4 s 3 v 2 l 0)) where the `n` `s` `v` `l` are transmit names for various meta-information types, and the applicable values for this content are 4 (for n), 3 (for s), 2 (for v) and 0 (for l). Only software which recognizes the ID "http://the.rating.service" would know how to interpret these categories and values.
The prior art includes various systems directed towards storing user preferences to select correspondingly encoded videos, and/or video streams. For multimedia streams, such as video and audio, rating an entire multimedia presentation using a single rating lacks flexibility. For example, one scene containing violence or sexually explicit content in a 2-hour video can result in the video receiving a high violence or high sexual content rating, thus blocking it from being viewed based on most user specifications.
For example, U.S. Pat. No. 4,930,160, entitled "Automatic Censorship of Video Programs," issued May 29, 1990 to Vogel, is directed to using classification codes to switch from a first video stream to an alternative video stream previously selected by the viewer. In addition to the aforementioned lack of flexibility, the censorship standards utilized under this proposal would likely come from a central censorship authority. This approach also requires the participation of the broadcasters if it is to be effective.
Another example, U.S. Pat. No 5,550,575, entitled "Viewer Discretion Television Program Control System," issued Aug. 27, 1996 to West et al., provides both time and content controls for multiple and variable numbers of viewers. The controls however, are at the granularity of the entire video.
Still another example, U.S. Pat. No. 5,434,678, entitled "Seamless Transmission of Non-Sequential Video Segments," was issued Jul. 18, 1995, to Abecassis. Abecassis is directed to the selective retrieval and seamless transmission of non-sequentially stored video segments of a variable content video program, responsive to a viewer's pre established video content preferences. Here, video segments from a single source can be selected by applying video content preferences to a video segment map. This approach also requires the generation of the variable content video program and the participation of the broadcaster, if it is to be effective.
Thus, the need remains for a system and method for rating and flexibly modifying multimedia content so that specific objects, for example a portion of a single video frame or sample of audio, can be dynamically masked, filtered, or modified according to the user's content specification. The need also remains for a system which does not require the generation of customized or variable content, or the participation of the broadcaster to be effective. The present invention addresses such a need.
Moreover, the need remains for such a video delivery system and method within an Internet and World Wide Web compatible transmission system such as HTTP. Furthermore, there is a need for a system which can be flexibly applied in the presence of a hierarchy of nodes. The present invention addresses such a need.